Pneumatically operable mechanism for doffing bobbins



Sept 6, 1969 F. K. WACHENDORF 3,456,863

PNEUMATICALLY OPERABLE MECHANISM FOR DOFFING BOBBINS 3 Sheets-Sheet 1 Filed Sept. 20, 1968 Zvxv MAY/XV AI// I/W [A TORJ FR/EDR/CH KARL WAU/E/VDOBF A TTOR/VE Y8 P 1969 F. K. WACHENDORF' 3,466,863

PNEUMATICALLY OPERABLE MECHANISM FOR DOFFING BOBBINS Filed Sept. 20, 1968 3 Sheets-Sheet 2 l5 H v I I 1 I 1 W ,av/m AY AWAY/N/N I N VE N 7' 0R FRIEDRICH KARL WACHEA DORF A7 ORA/5Y5 Sept. 16, 1969 F. K. WACHENDORF PNEUMATICALLY OPERABLE MECHANISM FOR DOFFING BOBBINS Filed Sept. 20, 1968 3 Sheeis-Sheet 5 I/Vl/E/VTUR: FRIEDRICH KARL WACHf/VOORF By a w, g i g A T708 N575 United States Patent 3,466,863 PNEUMATICALLY OPERABLE MECHANISM FOR DOFFING BOBBINS Friedrich Karl Wachendorf, Eggestedt, Kreis Osterholz, Germany, assignor to Atlas-MaK Maschinenbau G.m.b.H., Kiel-Friedrichsort, Germany Filed Sept. 20, 1968, Ser. No. 761,247 Claims priority, application Germany, Sept. 26, 1967, A 28,439 Int. Cl. D01h 9/00 US. Cl. 5752 7 Claims ABSTRACT OF THE DISCLOSURE The invention provides a pneumatically operable mechanism for releasing the tightly seated fully wound cops from the cut out spindles of ring spinning and doubling frames, which comprises a ring rail, a fork rail for engaging the undersides of the cops and, by lifting, loosening the same, said fork rail being mounted on vertically movable sliders which stand on a flexible inflatable tube extending along the length of the machine frame, the cross section of said inflatable tube when fully inflated corresponding to the lift of said fork rail and the pressure medium for inflating and exhausting said inflatable tube being controlled by at least one electromagnetic threeway valve, whereas buffer elements mounted on said fork rail lift the ring rail of of the way.

Background of the invention This invention relates to a pneumatically operable mechanism for releasing the tightly seated fully wound cops from the cut out spindles of ring spinning and doubling frames, by lifting the cops by about one third of their length with the aid of a rail provided with means for engaging the undersides of the cops.

A lifting mechanism for cops in self-acting speed frames has already been proposed, which comprises a plurality of ram cylinders distributed along the length of the frame, said cylinders being adapted to lift a rail which engages the bottom ends of the tubes of the fully wound cops and raises them a fraction of their overall length for the purpose of loosening them on the spindles prior to doffing. This arrangement cannot be used for ring spinning frames because the ring rail would be in the way of the lifting action. The provision of a plurality of ram cylinders is not only expensive but it is also of doubtful value, particularly in ring spinning frames for winding on supercops which are tightly wound from high tensile manmade fiber yarns that squeeze the cardboard tubes together until they grip the spindles very tightly.

Considerable thrusts must be generated for lifting all the super-cops on one side of the frame. The provision of several ram cylinders for uniformly lifting the cops necessitates operating the cylinders hydraulically in series to achieve the necessary uniformity of action. This means that very high pressures must be available which can be generated only at the expense of major pressure generating means. The necessary uniformity could not be achieved by operating hydraulic or pneumatic cylinders in parallel because of unavoidable inequalities in the existing conditions of friction in the stuffing boxes of the rams.

The known mechanism provides a perforated plate carrying a movable plate for engaging the undersides of the tubes of the cops. In view of the considerable lifting thrusts needed for loosening the cops in ring spinning frames, this method of engaging the underside of the expendable tubes is very liable to cause damage. If a few reserve turns are required to be wound on the bare spindle, or if the yarn is guided over underwinding cups, pressure 3,466,863 Patented Sept. 16, 1969 "ice against the underside of a cardboard tube, even if this is reinforced, cannot be performed without interference with the spun yarn.

Summary of the invention It is therefore the object of the present invention to overcome the shortcomings of the prior arrangement and by the provision of control means and the operation of switches, to perform the operation of loosening the cops prior to dotfing in ring spinning frames as quickly as possible after the reserve turns have been wound on.

To attain this object the present invention provides a pneumatically operable mechanism for releasing the tightly seated fully wound cops from the cut out spindles of ring spinning and doubling frames, which comprises a ring rail; a rail equipped with forks for engaging the undersides of the cops and, by lifting, loosening the same; a flexible inflatable tube extending along the length of a machine frame, the cross section of said inflatable tube when fully inflated corresponding to the lift of said fork rail; vertically movable sliders mounting said fork rail and standing on said flexible inflatable tube; a compressed air supply pipe leading to the inflatable tube; at least one electromagnetic three-way valve in said compressed air supply pipe for controlling the compressed air for infiating and exhausting said inflatable tube, and buffer elements mounted on said fork rail to lift said ring rail out of the way.

The ring rail is preferably suspended from a chain which is kept taut by a weight or a spring.

A second electromagnetically operable three-way valve may be provided for admitting the pressure medium to an actuator cylinder, which by extending its piston rod defiects the chain to lift the ring rail out of the way.

The provision of the inflatable tube eliminates the otherwise necessary ram cylinders, and the frictional forces engendered in the guideways of the vertically movable sliders can be kept very small and uniform. The generated expanding pressure is thus fully available for lifting the cops by applying a uniform lifting thrust to all the cops on one side of the frame. The pressure may be provided by making use of a compressed air system. For eccelerating the lifting action the compressed air may also be stored in a compressed air receiver preceding the lifting mechanism.

Engagement of the underside of the cops is by means of a fork which acts directly on the package of yarn. In practice it has been found that the yarn is not dislocated or damaged by the lifting and loosening action. The forks may be kept clean simply by Wiping off any dirt.

The invention also comprises the provision of simple electrical limit switches for controlling the electromagnetically operable three-way valves to inflate the inflatable tube under the spindles and to exhaust the same for operating the fork rail by means of the sliders. The raised fork rail simultaneously displaces the ring rail above by interposed resilient buffers and the slack of the chain from which the ring rail is suspended is taken up by compensating weights which keep the chain taut. Such a mechanism requires the provision of a strong fork rail and associated sliders and a ring rail adapted to the contemplated purpose. This is an advantage in the construction and manufacture of new ring spinning frames.

Alternatively, the ring rail may be lifted first and the fork rail subsequently and independently thereof. In such a case a limit switch is adapted first to energize a time delay relay and at the same time to turn the magnetic valve in the pressure supply pipe into position for admitting pressure to lift the ring rail. The ring rail is lifted very quickly. The time delay relay then operates the magnetic valve for admitting pressure to lift the cops, causing all the cops to be lifted within a few seconds.

When the fork rail reaches its upper position a limit switch changes the magnetic valves to exhaust position, first for lowering the fork rail and then for lowering the ring rail. For accelerating the pneumatic action an air receiver may again be incorporated in the compressed air supply and the pressure pipes from the receiver may have a wide cross section to admit the compressed air and to lift the ring and fork rails quickly. The lifting of the ring rail to move it out of the way is effected by an actuator cylinder which extends its piston to form a kink in the chain from which the ring rail is suspended.

Brief description of the drawings Embodiments of the invention will now be described by way of example and with reference to the accompanying schematic drawings in which:

FIG. 1 is a fragmentary elevational view of a ring spinning frame showing the cops raised and the ring rail as well as the fork rail in their upper positions;

FIG. la shows the three-way valve in exhaust position;

FIG. 2 is a fragmentary elevational view of a ring spinning frame according to another embodiment provided with two three-way valves and showing the cops in lifted position;

FIG. 2a shows the two three-way valves in exhaust position;

FIG. 3 is a cross section taken on the line IIIIII of FIG. 1, and

FIG. 4 is a cross section similar to FIG. 3 but showing the ring rail and the fork rail in lowered positions.

Description of the preferred embodiments With reference to FIG. 1 there is provided a box-section stationary spindle rail 1 containing the driving mechanism for the spindles 2. Mounted on a tube 3 the top of each spindle 2 carries a fully wound package of yarn, more specifically a cop 4. The ring rail 6 which is suspended from chains is in its upper position, and the fork rail 7 and its forks 8 which engage the undersides of the cops 4 is likewise in its upper position. The fork rail 7 rests on vertically movable sliders 9 formed with profiled bottom plates 10. The sliders 9 slide verticallly in ways 11 in the stationary spindle rail 1. However, they could also be mounted in the machine frame itself or even on the floor.

Below the stationary spindle rail 1 a flexible inflatable tube 13 is contained in a U-section trough 12. Preferably this inflatable tube 13 is a flexible low-stretch internally rubberized oilfast polyester fabric. The external sheath of the inflatable tube 13 is so contrived that it is practically insensitive to external mechanical effects. The length of the inflatable tube 13 is roughly equal to that of the stationary spindle rail 1.

The bottom plates of the sliders 9, the sliders 9 themselves, the fork rail 7 and the cops 4 are lifted into their upper positions and any restoring springs 25 that may be provided are tensioned.

One end of the inflatable tube 13 may be conveniently sealed by a flat pipe strap 14. Alternatively also this end of the inflatable tube 13 may be closed by a plate 15 secured by an annular strap 16 as is used at the other end of the inflatable tube 13. A pressure pipe 19 is attached to the plate 15 at said other end and leads to an electromagnetically controlled three-way valve 20. The compressed air is supplied either by a compressor set or by a central supply of compressed air through a pipe 17. For storing a suflicient volume of compressed air to ensure a rapid lift of the cops 4 when the bearing pressure is low, an air receiver may be provided.

The lifting of the ring rail 6 by the fork rail 7 and interposed buffer elements 29 causes the ring rail chain 5 to slacken. The slackened ring rail chain 5 is kept taut by a compensating weight 30 or a spring. FIG. 1 shows the three-way valve in position for the admission of pressure in the arrowed direction. In FIG. 1a the compressed air supply pipe 17 is cut off and the air in the inflatable tube 13 can escape to exhaust through the valve 20 as indicated by an arrow.

An alternative arrangement for independently lifting the ring rail and the fork rail is illustratively shown in FIG. 2. A pressure pipe 19 is again attached to the plate 15, the admission and exhausting of the air being controlled by an electromagnetically controlled three-way valve 20. The compressed air supply pipe 17 contains a second electromagnetically controlled three-way valve 23 adapted through a pipe 22 to admit compressed air to a ram cylinder 21 containing a piston 24 which by its displacement pushes a kink into the chain 5, which normally runs horizontally over rollers 26, and which is kept taut by the weight of the ring rail 6. Displacement of the piston 24 thus lifts the ring rail 6 into its raised clearing position.

Contrary to FIGS. 1 to 3 the next FIG. 4 shows the starting position before lifting the cops, when the spinping operation has just been completed. The ring rail 6 is in its bottom position in which the yarn 27 is underwound to provide reserve turns 28 on the bottom end of the tube 3. These reserve turns 28 are pulled onto the bare upper part of the spindle 2 when the cop is doffed, and clamped by the next empty tube for winding on. The reserve turns 28 may also be wound on the bare spindle or they may be taken over an underwinding cup. This would prevent the tube 3 from being engaged from below for raising the cop. The inflatable tube 13 is shown deflated and rests on the floor of the U-section trough 12 squeezed together by the weight of the fork rail 7 and the tension of the restoring spring 25, if such a spring is provided.

In the embodiment according to FIG. 1 the position of the three-way valve 20 for exhausting the pressure can be changed to the admission of compressed air immediately the cops are fully wound. The inflatable tube 13 will then expand at once to its maximum size, lifting the fork rail 7 as well as the ring rail 6 by the interposed buffer elements 29. The cops 4 are thus loosened. A limit switch actuated by the fork rail 7 then returns the threeway valve 20 to exhaust position, permitting the ring rail 6 and the fork rail 7 to descend into their former positions by gravity. The cops 4 remain in their raised positions and can be doffed from the upper parts of the spindles without any effort.

The embodiment according to FIG. 2 functions as follows:

The pressure exhausting position of the three-way valves 20 and 23 after the last cops have been doffed is shown in FIG. 2a. When the spindles 2 have come to a stop at the end of the spinning operation the three-way valve 23 for lifting the ring rail 6 into clearing position is first placed into the pressure admitting position by an electromagnetic switch. a time delay relay then turns the other three-way valve 20 for lifting the cops into pressure admitting position. The ring rail 6 and the fork rail 7 attain their raised positions by the descent of the piston 24 and by the inflation of the inflatable tube 13. In its raised position the fork rail 7 actuates a limit switch for changing over the position of the three-way valve 20 and immediately afterwards the three-way valve 23 is likewise changed to exhaust position (FIG. 2a) by the operation of a time delay relay. The fork rail 7 and the ring rail 6 therefore both descend into their former positions (FIG. 4) whereas the loosened cops 4 remain loosely suspended on the taper ends of the spindles whence they can be manuallly or mechanically doffed.

What is claimed is:

1. A pneumatically operable mechanism for releasing the tightly seated fully wound cops from the cut out spindles of ring spinning and doubling frames, comprising (a) a ring rail;

(b) a rail equipped with forks for engaging the undersides of the cops and, by lifting, loosening the same;

(0) a flexible inflatable tube extending along the length of a machine frame, the cross section of said inflatable tube when fully inflated corresponding to the lift of said fork rail;

(d) vertically movable sliders mounting said fork rail and standing on said flexible inflatable tube;

(e) a compressed air supply pipe leading to the inflatable tube;

(f) at least one electromagnetic three-way valve in said compressed air supply pipe for controlling the compressed air for inflating and exhausting said inflatable tube, and

(g) buffer elements mounted on said fork rail to lift said ring rail out of the way.

2. A mechanism according to claim 1, wherein a bottom plate adapted to rest on said inflatable tube is associated with each vertically movable slider.

3. A mechanism according to claim 1, comprising a chain for the suspension therefrom of said ring rail, said chain being kept taut by a weight.

4. A mechanism according to claim 3, wherein a second electromagnetic three-way valve is incorporated in the compressed air supply pipe for pressurizing a ram cylinder containing a piston adapted to lift said ring rail out of the Way by deflecting said chain.

5. A mechanism according to claim 4, wherein said pressure supply pipe includes a compressed air receiver, the cross section of said pressure supply pipe between said compresed air receiver and said inflatable tube exceeding the cross section of said pressure supply pipe supplying the compressed air to said compressed air receiver.

6. A mechanism according to claim 1, comprising a chain for the suspension therefrom of said ring rail, said chain being kept taut by a spring.

7. A mechanism according to claim 1, wherein said inflatable tube for raising said fork rail is made of an internally rubberized polyester fabric externally protected to render it insensitive to mechanical effects, of the kind commercially available by the yard in any desired lengths.

References Cited UNITED STATES PATENTS 1,810,754 6/1931 Buddecke 5752 2,952,113 9/1960 Ingham 5752 2,962,856 12/1960 Ingham 57-52 JOHN PETRAKES, Primary Examiner 

